1. Field of the Invention
The present invention relates to a continuous in-line treatment process for wire drawing. More specifically, the invention relates to a continuous in-line dry brush treatment process for removing an oxide film from stainless steel rod or wire prior to drawing, continuous coating procedure for applying of lubricant carrier, and a post drawing brushing stage for removing residual drawing compounds comprising carrier coating and lubricant from the drawn wire.
2. Related Art
Conventional means for descaling rod or wire, or removing oxide from stainless steel wire, before drawing, typically include either passing the wire through a "pickling" tank containing acid, or, in the case of non-stainless steel, either passing the wire through a "pickling" tank containing acid, or mechanically descaling the wire by bending it or blasting it with abrasive particles. The wire is then coated with a lubricant and drawn. Once the wire is drawn, excess lubricant coating and any scale is removed from the wire according to conventional degreasing processes.
For example, U.S. Pat. No. 4,553,416 to Sudoh et al. is directed to a dry type continuous wire drawing process. Under this process, a steel wire to be drawn is mechanically descaled, coated with a lubricant and drawn through a drawing die. Mechanical descaling is achieved by passing the wire through a shot blaster, wherein shot particles are directed at the wire to remove any oxide film therefrom. Alternatively, a roll bender may be used to repeatedly bend and elongate the wire so that the scale layer is fissured and can be peeled off.
U.S. Pat. No. 5,201,206 to Russo discloses a continuous wire drawing process in which a mechanical descaler bending of the stock is used to remove scale from alloy steel wire prior to drawing and a buffer unit is used to remove carrier and lubricant by buffing with a plurality of buffer wheels.
U.S. Pat. No. 3,320,701 to Abrams et al. discloses a method for treating metal in connection with cold reduction operations using abrasive blast cleaning units for directing abrasive media against the upper and lower surfaces of a piece of metal.
U.S. Pat. No. 2,335,196 to Pecsok discloses a method for removing scale from metal sheets by passing a sheet through (1) a water spray to loosen the scale, then (2) a pair of breaker rolls that flex the sheet to aid in breaking up the scale into particles, then (3) a brushing station to lift and pick off the scale particles.
These conventional pickling and degreasing methods create hazardous conditions and can have an extremely detrimental impact on the environment and require high investment and process costs. In addition, mechanical descaling involving bending such as that disclosed in U.S. Pat. No. 2,335,196 to Pecsok is inapplicable to stainless steel wire because the thin layer of oxide film that forms on stainless steel wire is ductile and therefore cannot be removed by such mechanical descaling processes.